Do not display matches against

the right-hand side of a NOT operator in the output
of the FTS snippet() or offsets() functions. (CVS 6097)

FossilOrigin-Name: d44c84c0f77bd0fc4a9942177b6cae6d109b89b7

ext/fts3/fts3.c

@@ -3136,8 +3136,13 @@ static void snippetAppendMatch(
 
 /*
 ** Function to iterate through the tokens of a compiled expression.
+**
+** Except, skip all tokens on the right-hand side of a NOT operator.
+** This function is used to find tokens as part of snippet and offset
+** generation and we do nt want snippets and offsets to report matches
+** for tokens on the RHS of a NOT.
 */
-static int nextExprToken(Fts3Expr **ppExpr, int *piToken){
+static int fts3NextExprToken(Fts3Expr **ppExpr, int *piToken){
   Fts3Expr *p = *ppExpr;
   int iToken = *piToken;
   if( iToken<0 ){
@@ -3160,6 +3165,7 @@ static int nextExprToken(Fts3Expr **ppExpr, int *piToken){
       }
       p = p->pParent;
       if( p ){
+        assert( p->pRight!=0 );
         p = p->pRight;
         while( p->pLeft ){
           p = p->pLeft;
@@ -3173,16 +3179,32 @@ static int nextExprToken(Fts3Expr **ppExpr, int *piToken){
   return p?1:0;
 }
 
+/*
+** Return TRUE if the expression node pExpr is located beneath the
+** RHS of a NOT operator.
+*/
+static int fts3ExprBeneathNot(Fts3Expr *p){
+  Fts3Expr *pParent;
+  while( p ){
+    pParent = p->pParent;
+    if( pParent && pParent->eType==FTSQUERY_NOT && pParent->pRight==p ){
+      return 1;
+    }
+    p = pParent;
+  }
+  return 0;
+}
+
 /*
 ** Add entries to pSnippet->aMatch[] for every match that occurs against
 ** document zDoc[0..nDoc-1] which is stored in column iColumn.
 */
 static void snippetOffsetsOfColumn(
-  fulltext_cursor *pCur,
+  fulltext_cursor *pCur,         /* The fulltest search cursor */
-  Snippet *pSnippet,
+  Snippet *pSnippet,             /* The Snippet object to be filled in */
-  int iColumn,
+  int iColumn,                   /* Index of fulltext table column */
-  const char *zDoc,
+  const char *zDoc,              /* Text of the fulltext table column */
-  int nDoc
+  int nDoc                       /* Length of zDoc in bytes */
 ){
   const sqlite3_tokenizer_module *pTModule;  /* The tokenizer module */
   sqlite3_tokenizer *pTokenizer;             /* The specific tokenizer */
@@ -3217,10 +3239,15 @@ static void snippetOffsetsOfColumn(
     iRotorBegin[iRotor&FTS3_ROTOR_MASK] = iBegin;
     iRotorLen[iRotor&FTS3_ROTOR_MASK] = iEnd-iBegin;
     match = 0;
-    for(i=0; i<(FTS3_ROTOR_SZ-1) && nextExprToken(&pIter, &iIter); i++){
+    for(i=0; i<(FTS3_ROTOR_SZ-1) && fts3NextExprToken(&pIter, &iIter); i++){
-      int nPhrase = pIter->pPhrase->nToken;   /* Tokens in current phrase */
+      int nPhrase;                    /* Number of tokens in current phrase */
-      struct PhraseToken *pToken = &pIter->pPhrase->aToken[iIter];
+      struct PhraseToken *pToken;     /* Current token */
-      int iCol = pIter->pPhrase->iColumn;
+      int iCol;                       /* Column index */
+
+      if( fts3ExprBeneathNot(pIter) ) continue;
+      nPhrase = pIter->pPhrase->nToken;
+      pToken = &pIter->pPhrase->aToken[iIter];
+      iCol = pIter->pPhrase->iColumn;
       if( iCol>=0 && iCol<nColumn && iCol!=iColumn ) continue;
       if( pToken->n>nToken ) continue;
       if( !pToken->isPrefix && pToken->n<nToken ) continue;
@@ -3264,11 +3291,13 @@ static void snippetOffsetsOfColumn(
 ** the integer id of the left-most token in the expression tree headed by
 ** pExpr. This function increments *piLeft by the total number of tokens
 ** in the expression tree headed by pExpr.
+**
+** Return 1 if any trimming occurs.  Return 0 if no trimming is required.
 */
 static int trimSnippetOffsets(
-  Fts3Expr *pExpr, 
+  Fts3Expr *pExpr,      /* The search expression */
-  Snippet *pSnippet,
+  Snippet *pSnippet,    /* The set of snippet offsets to be trimmed */
-  int *piLeft
+  int *piLeft           /* Index of left-most token in pExpr */
 ){
   if( pExpr ){
     if( trimSnippetOffsets(pExpr->pLeft, pSnippet, piLeft) ){
@@ -3385,9 +3414,11 @@ static void snippetAllOffsets(fulltext_cursor *p){
   nColumn = pFts->nColumn;
   iColumn = (p->iCursorType - QUERY_FULLTEXT);
   if( iColumn<0 || iColumn>=nColumn ){
+    /* Look for matches over all columns of the full-text index */
     iFirst = 0;
     iLast = nColumn-1;
   }else{
+    /* Look for matches in the iColumn-th column of the index only */
     iFirst = iColumn;
     iLast = iColumn;
   }

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\s(benign)\svalgrind\serror\sthat\scan\soccur\sfollowing\smalloc\sfailure\swhile\sexecuting\sa\s'ROLLBACK\sTO\ssavepoint'\scommand.\s(CVS\s6096)
+C Do\snot\sdisplay\smatches\sagainst\r\nthe\sright-hand\sside\sof\sa\sNOT\soperator\sin\sthe\soutput\r\nof\sthe\sFTS\ssnippet()\sor\soffsets()\sfunctions.\s(CVS\s6097)
-D 2009-01-01T15:20:37
+D 2009-01-02T01:10:42
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 77635d0909c2067cee03889a1e04ce910d8fb809
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -53,7 +53,7 @@ F ext/fts2/mkfts2amal.tcl 974d5d438cb3f7c4a652639262f82418c1e4cff0
 F ext/fts3/README.syntax a19711dc5458c20734b8e485e75fb1981ec2427a
 F ext/fts3/README.tokenizers 998756696647400de63d5ba60e9655036cb966e9
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c 3aa6aef1eadc44606f6ed3c841062735a5210077
+F ext/fts3/fts3.c 4e0d3b1b8ad133e0cd641e9eaa56015ad0466cd6
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
 F ext/fts3/fts3_expr.c 98fe92f6888c306734ed9332a24383dde77c25aa
 F ext/fts3/fts3_expr.h b5412dcf565c6d90d6a8c22090ceb9ed8c745634
@@ -690,7 +690,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P ccfe4580ac7ba9add0e69c786a9a3a43d69b7753
+P 9ff8598f3be123a244f71b45e77af913b836504a
-R 55e5da6452ac7bf13b968c8f36ed538b
+R 2cdfa5be7870dcec4ac66bcd1ad84dbe
-U danielk1977
+U drh
-Z fe12888ee4a3f9d606558994dc2f8d82
+Z a59547509372bc8abd2b95e6b7d6a629

manifest.uuid

@@ -1 +1 @@
-9ff8598f3be123a244f71b45e77af913b836504a
+d44c84c0f77bd0fc4a9942177b6cae6d109b89b7